Kinematic equations Quiz 1

Question 1

A boy went to a park and sees a bird flying in the sky at a certain height from the ground level, he throws a ball in the upward direction with a speed of $$V=10\sqrt{2} m{{s}^{-1}}$$. The speed of ball in the return journey $$(	ext{falling downwards})$$ at a height of $$5 m$$ from ground will be-

Accepted Answer

$$10 m{{s}^{-1}}$$

Answer

$$10\sqrt{2} m{{s}^{-1}}$$

Answer

$$15 m{{s}^{-1}}$$

Answer

$$5 m{{s}^{-1}}$$

Question 2

Ram throws a ball horizontally with initial velocity  $$u$$, after $$2 s$$ he observes the velocity of ball equal to $$15 m{{s}^{-1}}$$ and after $$4 s$$ it changed to $$25 m{{s}^{-1}}$$ this rapid change in velocity made him curious to know about the motion of ball, so he started calculating the initial velocity and acceleration of ball which will be equal to- $$ \ $$<img  src="https://cmds-vedantu.s3.ap-southeast-1.amazonaws.com/prod/question-sets/ba5f8325-716a-43c0-931a-fe6b06e3c6159140589872912611015.png"/>

Accepted Answer

$$u=5 m{{s}^{-1}},a=5 m{{s}^{-2}}$$

Answer

$$u=2 m{{s}^{-1}},a=2 m{{s}^{-2}}$$

Answer

$$u=5 m{{s}^{-1}},a=10 m{{s}^{-2}}$$

Answer

$$u=10 m{{s}^{-1}},a=5 m{{s}^{-2}}$$

Question 3

Tesla launches a new automatic car in India whose displacement on empty road is given by $$s=7{{t}^{3}}+4{{t}^{2}}+3t+4$$m, due to this variation in displacement only physics professors can drive this car. So Mehta sir went to the showroom and did a test drive of the car and wants to calculate instantaneous velocity of car at $$t=2 s$$. the calculated velocity will be-

Accepted Answer

$$103 m{{s}^{-1}}$$

Answer

$$83 m{{s}^{-1}}$$

Answer

$$90 m{{s}^{-1}}$$

Answer

$$72 m{{s}^{-1}}$$

Question 4

A high speed vehicle id travelling along a horizontal direction. The acceleration-time graph of its motion is shown in figure. Now he is measuring velocity at $$t=10 s$$ and $$t=20 s$$ so he can plot a velocity-time graph of its motion. The $$V-t$$ graph will be given by-<img  src="https://cmds-vedantu.s3.ap-southeast-1.amazonaws.com/prod/question-sets/544f6896-b8b6-4dd2-8ed6-c9015f81c0e52330584752926514655.png"/>

Accepted Answer

Answer

Answer

Answer

Question 5

A man $$A$$ is standing on a hill of height of $$15 m$$ from the ground and his friend $$B$$ is standing on the ground just nearby the hill as shown in figure. Now, $$B$$ wants to catch a ball thrown by his friend $$A$$ but with one condition that he can catch a ball with a maximum of $$20 m{{s}^{-1}}$$ of speed. Now man $$A$$ throws a ball in an upward direction which eventually comes down to $$A$$ after some time. The maximum speed by which $$A$$ throws a ball so $$B$$ can catch it easily will be $$ \ $$<img  src="https://cmds-vedantu.s3.ap-southeast-1.amazonaws.com/prod/question-sets/0f853edc-ef79-4576-85e7-d2ba845aaffc716263527327147787.png"/>

Accepted Answer

$$10 m{{s}^{-1}}$$

Answer

$$20 m{{s}^{-1}}$$

Answer

$$15 m{{s}^{-1}}$$

Answer

$$25 m{{s}^{-1}}$$