Answer:
a.
b.1058 N
Explanation:
We are given that
Mass of each dog,M=18.5 kg
Mass of sled with rider,m=250 kg
a.Average force,F=185 N


By Newton's second law



b.By Newton's second law

Substitute the values

Hence, the force in the coupling between the dogs and the sled=1058 N
<h3>No:1</h3>
The object is moving with constant or uniform acceleration and in average speed
<h3>No:-2</h3>
The object is de accelerating
<h3>No:-3</h3>
The object deaccelerated and came to rest so fast.
<h3>No:-4</h3>
The object moves slowly first then accelerated.
<h3>No:-5</h3>
The object accelerated at first so fast then move with constant acceleration then again accelerated .
B. Decreasing surface area of a solid reactant. The more surface area showing, the quicker the reaction rate.
Answe
given,
mass of the bar, m = 30 Kg
distance of rise, h = 0.60 m
Assuming the efficiency = 25 %
energy from the pizza slice = 300 C = 1260 kJ
To consume Energy from the pizza bar is to be pulled several number of time.
( energy from pizza ) x (efficiency) = n m g h
n is the number of lift
( 1260 x 10³) x (0.25) = n x 30 x 9.8 x 0.6

n = 1786 times.
Weightlifter should lift bar 1786 times to burn off the energy.