Answer:
Kinetic energy = (1/2) (mass) (speed)²
Before slowing down, the car's speed is 25 m/s,
and its kinetic energy is ...
(1/2) (1,500 kg) (25 m/s)²
= (1/2) (1,500 kg) (625 m²/s²)
= 468,750 joules .
After slowing down, the car's speed is 15 m/s,
(1/2) (1,500 kg) (15 m/s)²
= (1/2) (1,500 kg) (225 m²/s²)
= 168,750 joules.
The car lost (468,750 - 168,750) = 300,000 joules
and you heard it from the KING
(1) 2 × 10^–2 m (3) 2 × 10^0 m
(2) 2 × 10^–1 m (4) 2 × 10^1 m
The velocity of the pillow after 4 seconds is -45.2 m/sec and this can be determined by using the velocity formula.
Given :
A pillow is thrown downward with an initial speed of 6 m/s.
The equation of velocity is used in order to determine the pillow's velocity after 4 seconds.
v = u + at
where 'v' is the final velocity, 'a' is the acceleration due to gravity, 'u' is the initial velocity, and 't' is the time.
Now, substitute the known terms in the above equation in order to determine the pillow's velocity after 4 seconds.
v = -6 - 9.8 (4)
Simplify the above equation.
v = -6 - 39.2
v = -45.2 m/sec
So, the velocity of the pillow after 4 seconds is -45.2 m/sec.
For more information, refer to the link given below:
Given :
Initial velocity, u = -6 m/s.
Time taken, t = 4 seconds.
Acceleration due to gravity, .( Here negative sign means downward direction )
To Find :
Velocity after 4 seconds.
Solution :
By equation of motion.
v = u + at
Here , a = g.
v = u + gt
v = -6 + (-9.8)×4
v = -6 + (-39.2)
v = -45.2 m/s
Therefore, velocity after 4 seconds is -45.2 m/s.
Hence, this is the required solution.
Compound microscope
Corrective eyeglasses
Slide projector
Answer:
radio waves
microwaves