Question

1. A net force of 15 N is exerted on an encyclopedia to cause it to accelerate at a rate of 5 m/s². Determine the mass of the encyclopedia.

2. A car of mass 250kg applied brakes to cause it's change in velocity from 16 m/s to 4m/s in 2 seconds. What force must be applied by the brakes?


3. A cyclist is travelling at 15m/s. She applies brakes so that she does not collide with a wall 18m away. What force must the brakes apply on the wheels?


4. Suppose that a table is accelerating at a rate of 2 m/s² If the net force is tripled and the mass is halved, then what is the new acceleration of the table?


5. A 5.0 kg mass has its velocity change from 8.0 m/s east to 2.0 m/s east. 
Find the object's change in momentum.​

Answer 1

Explanation:

1 F=15N

a = 5 m/s whole square

we know F=ma

m=F/a

15/3 = 3kg

2. m= 250 kg

u or initial velocity = 16 m/s

v or final velocity. = 4 m/s

time in seconds = 2 seconds

so first. a=v-u/t

a= 4-16/2

a= -12/2 = -6 m/s whole square sorry whole option is not available

3. u=15m/s

v= 0 as she applies brake v=0

displacement or s is 18 m

so the formula Wil be

v square=u square +2as

0= 15×15+2×a×18

36a=-225

a= -225/36 that is -6.25 meter per second square

- sign indicates that she has to decelerate at the rate of 6.25 meter per second square

4. a= 2 meter per second square

F = 3N

m= 1/2

a= F/m

3/1/2 that is 6 meter per second square

so total acceleration 6+2 that is 8 meter per second square

5. m= 5 kg 5.0 means 5

u= 8 meter per second

v= 2 meter per second

so here is the formula

p= m(v- u)

5 ( 8-2)

that is 5×6 = 30 kg m/s

p is for momentum