Answer:
the work done by the lawnmower is 236.14 J.
Explanation:
Given;
power exerted by the lawnmower engine, P = 19 hp
time in which the power was exerted, t = 1 minute = 60 s.
1 hp = 745.7 watts
The work done by the lawnmower is calculated as follows;
Therefore, the work done by the lawnmower is 236.14 J.
(2) impulse is a vector quantity. Energy has no direction, nor does power. Work is a dot product of vector quantities, which makes it a scalar.
<u>Answer</u>
= 9.25 m/s
<u>Explanation</u>
The Newton's second law of motion states that, the change in momentum is directly propotional to the force producing it and it takes place in the direction of force.
F = ma
f = m(v-u)/t
ft = m(v-u)
∴ 55 × 45/1000 = 0.060(v - -32)
2.475 = 0.06(v + 32)
2.475/0.6 = v + 32
41.25 = v + 32
v = 41.25 -32
= 9.25 m/s
KE = (1/2) (mass) (speed)²
KE = (1/2) (0.5 kg) (10 m/s)²
KE = (1/2) (0.5 kg) (100 m²/s²)
KE = (0.25 kg) (100 m²/s²)
KE = 25 Joules
