Answer:
The force needed to slow down the car is, F = 67.5 N
Explanation:
Given data,
The mass of the car, m = 15 kg
The initial velocity of the car, V = 60 m/s
The final velocity of the car, v = 15 m/s
The time period of deceleration, t = 10 s
The difference in the momentum of the car is,
mV - mv = 15(60 - 15)
= 675 kg m/s
The rate of change in momentum of the car gives the force acting on it.
F = (mV - mu) / t
Substituting the values,
F = 675 / 10
= 67.5 N
Hence, the force needed to slow down the car is, F = 67.5 N
Answer:
ΔU = -70 J
Explanation:
ΔU = Q − W
where ΔU is the change in internal energy,
Q is the heat absorbed by the system,
and W is the work done by the system (on the surroundings).
30 J of thermal energy is released, so Q = -30 J.
40 J of work is done by the system, so W = 40 J.
Therefore, the change in internal energy is:
ΔU = -30 J − 40 J
ΔU = -70 J
If you really have nothing else but time, then you can't. There must be some other shred of information. Search around. Look under rocks.
It a because I learn it in class today
Answer:
The original dimensions of the building is 95 ft × 38 ft.
Explanation:
Let the original length be 'l' and original width be 'w'.
Given:
Original length (l) = 
Original width = 'w'.
So, 
Now, as per question:
Length and width is increased by 7 ft.
So, new length (l') = 
New width (w') = 
New perimeter (P) = 266 ft
Perimeter is given as:
Therefore, original width = 38 ft.
Original length is, 
Hence, the original dimensions of the building is 95 ft × 38 ft.
