Answer:
Explanation:
AVerage acceleration is the cjange in velocity with time
a = v-u/t
v is the final velocity = 48m/s
u is the initial velocity = 40m/s
t is the time = 6.5s
a = 48-40/6.5
a = 8/6.5
a = 1.23m/s²
Hence the magnitude of the car’s average acceleration during this period is 1.23m/s²
Answer:
(A) It will take 22 sec to come in rest
(b) Work done for coming in rest will be 0.2131 J
Explanation:
We have given the player turntable initially rotating at speed of 
Now speed is reduced by 75 %
So final speed 
Time t = 5.5 sec
From first equation of motion we know that '

(a) Now final velocity 
So time t to come in rest 
(b) The work done in coming rest is given by

Answer:
False
Explanation:
The 3 important steps to a perfect forehand in tennis are Preparation,Backswing and Swing and contact.
Answer:
P = 7500 [W]
Explanation:
First We must use Newton's second law to find the force. Newton's Second Law tells us that the sum of forces on a body is equal to the product of mass by acceleration.
∑F = m*a
where:
m = mass = 150 [kg]
a = acceleration = 5 [m/s²]
![F = 150*5\\F = 750 [N]](https://tex.z-dn.net/?f=F%20%3D%20150%2A5%5C%5CF%20%3D%20750%20%5BN%5D)
We know that the work is determined by multiplying the force by the distance, in this way the units of the work are [N*m] which corresponds to 1 Joule [J].
And the power is determined by dividing the work by the time, in this way we have that [J/s] corresponds to 1 [W].
We must convert the speed from kilometers per hour to meters per second.
![36[km/hr]*1000[\frac{m}{1km}]*[\frac{1hr}{3600s} ]=10 [m/s]](https://tex.z-dn.net/?f=36%5Bkm%2Fhr%5D%2A1000%5B%5Cfrac%7Bm%7D%7B1km%7D%5D%2A%5B%5Cfrac%7B1hr%7D%7B3600s%7D%20%5D%3D10%20%5Bm%2Fs%5D)

where:
P = power [W]
F = force = 750 [N]
v = 10 [m/s]
![P = 750*10\\P = 7500 [W]](https://tex.z-dn.net/?f=P%20%3D%20750%2A10%5C%5CP%20%3D%207500%20%5BW%5D)