Answer:
Force, F = 77 N
Explanation:
A child in a wagon seem to fall backward when you give the wagon a sharp pull forward. It is due to Newton's third law of motion. The forward pull on wagon is called action force and the backward force is called reaction force. These two forces are equal in magnitude but they acts in opposite direction.
We need to calculate the force is needed to accelerate a sled. It can be calculated using the formula as :
F = m × a
Where
m = mass = 55 kg
a = acceleration = 1.4 m/s²

F = 77 N
So, the force needed to accelerate a sled is 77 N. Hence, this is the required solution.
Answer:
b. 0.6m/s, 0.7m/s, 0.61m/s, 0.62m/s
Explanation:
Precision of a measurement is the closeness of the experimental values to one another. Hence, experimental measurements are said to be precise if they are close to each other irrespective of how close they are to the accepted value. Precision can be determined by finding the range of each experimental value. The measurement with the LOWEST RANGE represents the MOST PRECISE.
Note: Range is the highest value - lowest value
Set A: 1.5 - 0.8 = 0.7
Set B: 0.7 - 0.6 = 0.1
Set C: 2.4 - 2.0 = 0.4
Set D: 3.1 - 2.9 = 0.2
Set B has the lowest range (0.1), hence, represent the most precise value.
Answer:
1- b: 2- a : 3- c : 4- d
Explanation:
it starts 2 move away from strting point, then no motion, then moves toward the start, the slows up.
Uhh it is used to detirmine heat