science
Grade-7
Easy
Question
A car moving at a velocity of 6.5 m/s increases its velocity uniformly to 78 m/s in 10 s. Work out its acceleration with a proper sign.
- + 7.15 m/s2
- +8.2 m/s2
- -7.15 m/s2
- +-8.25 m/s2
Hint:
Final velocity(v) = Initial velocity(u) + acceleration(a) 
time(t).
The correct answer is: + 7.15 m/s2
Given:
Initial velocity (u) = 6.5ms-1
Final velocity (v) = 78ms-1
Time taken (t) = 10s
Acceleration (a) =?
Formula:
v = u + at
Solution:
ANSWER:
acceleration of a car is +7.15ms-2
Positive acceleration means the direction of acceleration is same as of the direction of velocity.
Related Questions to study
science
Pick the odd one out.
Pick the odd one out.
scienceGrade-7
science
The following table shows the velocity of a moving car at different timestamps. The car is undergoing ___.
| Timestamp |
Velocity in m/s |
| 11:00 |
34 |
| 11:05 |
32 |
| 11:10 |
27 |
| 11:15 |
18 |
| 11:20 |
24 |
| 11:25 |
43 |
| 11:30 |
49 |
Acceleration is the rate of change of velocity.
The following table shows the velocity of a moving car at different timestamps. The car is undergoing ___.
| Timestamp |
Velocity in m/s |
| 11:00 |
34 |
| 11:05 |
32 |
| 11:10 |
27 |
| 11:15 |
18 |
| 11:20 |
24 |
| 11:25 |
43 |
| 11:30 |
49 |
scienceGrade-7
Acceleration is the rate of change of velocity.
science
Which of the following is/are true for a freefall?
a. It is a uniform motion in which an object falls towards the center of the earth.
b. It is an accelerated, non-uniform motion in which an object falls towards the center of the earth.
c. It is a uniformly accelerated motion.
d. The acceleration due to gravity is 9.8 m/s2.
Which of the following is/are true for a freefall?
a. It is a uniform motion in which an object falls towards the center of the earth.
b. It is an accelerated, non-uniform motion in which an object falls towards the center of the earth.
c. It is a uniformly accelerated motion.
d. The acceleration due to gravity is 9.8 m/s2.
scienceGrade-7
science
Which of the following remains constant in a uniform circular motion?
Which of the following remains constant in a uniform circular motion?
scienceGrade-7
science
Which of the following is/are true for a uniform circular motion?
a. It is an accelerated motion.
b. The speed of the body keeps on constantly changing throughout the motion.
c. The velocity of the body keeps constantly changing throughout the motion.
d. The acceleration of the body is directed along with the velocity at all points of motion.
Which of the following is/are true for a uniform circular motion?
a. It is an accelerated motion.
b. The speed of the body keeps on constantly changing throughout the motion.
c. The velocity of the body keeps constantly changing throughout the motion.
d. The acceleration of the body is directed along with the velocity at all points of motion.
scienceGrade-7
science
What is the direction of positive acceleration w.r.t. the velocity of a moving body?
What is the direction of positive acceleration w.r.t. the velocity of a moving body?
scienceGrade-7
science
A moving body is said to be decelerating if it is ____.
A moving body is said to be decelerating if it is ____.
scienceGrade-7
science
A moving body is said to be positively accelerating if it is ____.
Example : when person jumps off the height.
A moving body is said to be positively accelerating if it is ____.
scienceGrade-7
Example : when person jumps off the height.
science
Which of the following remains constant during freefall?
Which of the following remains constant during freefall?
scienceGrade-7
science
Uniform circular motion is a/an ___ motion.
Uniform circular motion is a/an ___ motion.
scienceGrade-7
science
The SI unit of acceleration is ___.
The SI unit of acceleration is ___.
scienceGrade-7
science
The rate of change of ___ is called acceleration.
The rate of change of ___ is called acceleration.
scienceGrade-7
science
Selena is classifying different moving objects into two categories, i.e., rotational motion and periodic motion. She has the following motions to classify:
a. The motion of a swing
b. The motion of the Earth around the Sun
c. The motion of a giant wheel
d. The motion of the blades of a fan at a particular speed
e. The motion of the hands of a clock
f. The motion of a roller coaster
g. The motion of a merry-go-round
h. The motion of a pendulum
She could identify some of the above objects, which can be put in both categories. What are those?
Selena is classifying different moving objects into two categories, i.e., rotational motion and periodic motion. She has the following motions to classify:
a. The motion of a swing
b. The motion of the Earth around the Sun
c. The motion of a giant wheel
d. The motion of the blades of a fan at a particular speed
e. The motion of the hands of a clock
f. The motion of a roller coaster
g. The motion of a merry-go-round
h. The motion of a pendulum
She could identify some of the above objects, which can be put in both categories. What are those?
scienceGrade-7
science
A man is driving a car at a constant speed. What is the state of the man w.r.t. a person sitting inside the car?
A man is driving a car at a constant speed. What is the state of the man w.r.t. a person sitting inside the car?
scienceGrade-7
science
A man is driving a car at a constant speed. What is the state of the man w.r.t. a tree on the road?
A man is driving a car at a constant speed. What is the state of the man w.r.t. a tree on the road?
scienceGrade-7
