Motion for Grade 9

Select all that apply

v = ___________

• $\frac{2\pi r}{t}$

• $ut\ +\frac{1at^2}{2\ }$

• $at$

• $\frac{v}{t}$

A particle experiences constant acceleration for 20 seconds after starting from rest. If it travels a distance s1​ in the first 10 seconds and distance s2​ in the next 10 seconds, then

• s₂ = s₁

• s₂ = 2s₁

• s₂ = 3s₁

• s₂ = 4s₁

Is Magnitude of velocity Speed?

• Yes

• No

Assertion- A body cannot have zero velocity while having acceleration

Reason - Acceleration can only be zero in constant velocity

• Assertion and reason are true and reason is the correct explanation of assertion

• Assertion and reason are true and reason isnot the correct explanation of assertion

• Assertion is true but Reason is false

• Assertion is false but Reason is true

• Both are false

A particle moves in a straight line. For half of the time it travels at v₁ velocity and for the other half it travels at v₂. The average velocity is

• $\frac{2v_1v_2}{2}$

• $\frac{v_1\ -\ v_{2_{ }}}{2}$

• $v_1+\ v_2$

• $\frac{v_1\ +\ v_2}{2}$

m is the SI unit of _______________ and ______________ ( separated by comma)

 $s\ -\ \frac{1\ at^2}{2}\ =$  

The SI unit of angular velocity is

A boy wants to walk 5 km in 45 mins . He is walking around a circular park with diameter 210 m . Find out how many rounds of the park does he have to take and what should be his average speed?

A racing car reaches a speed of 50 m/s. At this instant it begins a uniform negative acceleration using a parachute and a braking system and comes to rest 50 s later. How far does the car travel after acceleration starts. ( show calculation use '^' for raised to the power and DON'T PRESS ENTER)