Answer:
a = 0 m/s²
Explanation:
given,
car moving at steady velocity = 100 Km/h
1 km/h = 0.278 m/s
100 Km/h = 27.8 m/s
time of acceleration = 100 s
acceleration is equal to change in velocity per unit time.

change in velocity of the car is 27.8 - 27.8 = 0

a = 0 m/s²
If the car is moving with steady velocity then acceleration of the car is zero.
Hence, the acceleration of the car is equal to a = 0 m/s²
Answer:

Explanation:
We know that for circular motion the centripetal acceleration
is:

where v is the speed and r is the radius.
The centripetal acceleration for the astronaut must be the gravitational acceleration due to the gravity, as there are no other force. So
.
The radius of the orbit must be the radius of the Moon, plus the 270 km above the surface




We can obtain the speed as:






And this is the orbital speed.
Mercury, Venus, Earth, and Mars are considered terrestrial planets because those planets are mainly composed of metal or rock and are closest to the sun.
Answer:
a) 2.85 kW
b) $ 432
c) $ 76.95
Explanation:
Average price of electricity = 1 $/40 MJ
Q = 20 kW
Heat energy production = 20.0 KJ/s
Coefficient of performance, K = 7
also
K=(QH)/Win
Now,
Coefficient of Performance, K = (QH)/Win = (QH)/P(in) = 20/P(in) = 7
where
P(in) is the input power
Thus,
P(in) = 20/7 = 2.85 kW
b) Cost = Energy consumed × charges
Cost = ($1/40000kWh) × (16kW × 300 × 3600s)
cost = $ 432
c) cost = (1$/40000kWh) × (2.85 kW × 200 × 3600s) = $76.95