The mass is 20 kg, initial speed is 30 m/s and the final speed is 0 m/s (rest),
while the force is 15 N
Using second newton's law of motion which states that the rate of change in momentum is directly proportional to the resultant force. Then
Ft = MV-MU
15 t = 20 (0-3)
15t = -60
t = -4 sec ( negative because the force is acting on opposite direction to the motion)
Therefore, the time taken is 4 seconds
Answer:
Explanation:
When two people carry a weight placing it on a very light board then we neglect the weight of the board and the board acts like a beam with two mass placed over it and two end point supports are here provided by men.
Then balancing the forces in the vertical direction, weight of the motor is:
These men are able to carry the motor in equilibrium condition because they have placed the motor (considering it a point mass) at a position such that the moment due to the lifting forces are equal and opposite.
KE = 8887.5 J
<h3>Further explanation</h3>
Given
speed = 15 m/s
weight = 79 kg
Required
KE-Kinetic energy
Solution
Energy is the ability to do work
Energy because its motion is expressed as Kinetic energy (KE) which can be formulated as:
Input the value :
KE = 1/2 x 79 kg x 15² m/s²
KE = 8887.5 J
<span>A lubricant such as oil, grease, graphite powder can reduce the friction between two surfaces. Or using metal balls to space them and reduce the contact surface area as used in ball bearings.</span>
Answer:
15.6m/s
Completed Question;
For a short period of time, the frictional driving force acting on the wheels of the 2.5-Mg van is N= 600t^2 , where t is in seconds. If the van has a speed of 20 km/h when t = 0, determine its speed when t = 5
Explanation:
Mass m = 2500kg
Speed v1 = 20km/h = 20/3.6 m/s = 5.556 m/s
To determine speed v2;
Using the principle of momentum and impulse;
mv1 + ∫₀⁵ F dt = mv2
