Answer:
The answer to your question is: F = 50 N
Explanation:
Data
mass = 1000 kg
acceleration = 0.05m/s2
F = ?
Formula
F = m x a
Substitution
F = 1000 kg x 0.05 m/s2 = 50 kgm/s2 = 50 N
Mike is applying a force of 50 N to the car.
<span>k = 1.7 x 10^5 kg/s^2
Player mass = 69 kg
Hooke's law states
F = kX
where
F = Force
k = spring constant
X = deflection
So let's solve for k, the substitute the known values and calculate. Don't forget the local gravitational acceleration.
F = kX
F/X = k
115 kg* 9.8 m/s^2 / 0.65 cm
= 115 kg* 9.8 m/s^2 / 0.0065 m
= 1127 kg*m/s^2 / 0.0065 m
= 173384.6154 kg/s^2
Rounding to 2 significant figures gives 1.7 x 10^5 kg/s^2
Since Hooke's law is a linear relationship, we could either use the calculated value of the spring constant along with the local gravitational acceleration, or we can simply take advantage of the ratio. The ratio will be both easier and more accurate. So
X/0.39 cm = 115 kg/0.65 cm
X = 44.85 kg/0.65
X = 69 kg
The player masses 69 kg.</span>
Efficiency or 
is calculated by formula: 
where 
also efficiency has no unit.
Now put in the data and calculate the efficiency.
The efficiency of the machine is 0.8
If you want to get percentage just multiply by 100 and you get 80%
Hope this helps.
r3t40
If an object is moving, then its speed and the magnitude
of its velocity aren't zero.
If its velocity is constant (speed doesn't change and it's
moving in a straight line), then its acceleration is zero.
Looks like choice-D sums it up nicely.
