Answer:
Power is the rate at which work is done.
Explanation:
The work done divided by total time taken is called power of an object. The SI unit of power is watts. It is denoted by W. Its expression is given by :
Since, W = F.d
Since,
It is also equal to the product of force and velocity. Hence, the correct option is (c).
Answer:
3.06m/s² to the east
Explanation:
Given parameters:
Mass of car = 2.5 x 10³kg
Force acting on the car = 7.65 x 10³N
Unknown:
Acceleration of the car = ?
Solution:
From Newton's second law of motion:
Force = mass x acceleration
Acceleration = =
= 3.06m/s² to the east
Answer:
mu = 0.56
Explanation:
The friction force is calculated by taking into account the deceleration of the car in 25m. This can be calculated by using the following formula:
v: final speed = 0m/s (the car stops)
v_o: initial speed in the interval of interest = 60km/h
= 60(1000m)/(3600s) = 16.66m/s
x: distance = 25m
BY doing a the subject of the formula and replace the values of v, v_o and x you obtain:
with this value of a you calculate the friction force that makes this deceleration over the car. By using the Newton second's Law you obtain:
Furthermore, you use the relation between the friction force and the friction coefficient:
hence, the friction coefficient is 0.56