Answer: - 7500N
Explanation:
Given the following :
Initial Velocity of car = 108km/hr
Time taken to stop after applying brakes = 4s
Mass of passengers in car = 1000kg
Force exerted by the brakes on the car =?
After 4s, then final Velocity (V) = 0
Initial Velocity (u) of the car = 108km/hr
108km/hr = (108 × 1000)m ÷ (3600)s = 30m/s
Force exerted = mass(m) × acceleration(a)
Acceleration of car = Change in Velocity with time
a = (v - u) / t
a = (0 - 30) / 4
a = - 30/ 4
a = - 7.5m/s^2
Therefore,
Force exerted = mass(m) × acceleration(a)
Force exerted = 1000kg × (-7.5)m/s^2
Force exerted = - 7500N
Objects like apples, wood, and sponges are less dense than water. They will float. Many hollow things like empty bottles, balls, and balloons will also float.
Answer:
Same direction to produce maximum magnitude and opposite direction to produce minimum magnitude
Explanation:
Let a be the angle between vectors A and B. Generally when we add A to B, we can split A into 2 sub vectors, 1 parallel to B and the other perpendicular to B.
Also let A and B be the magnitude of vector A and B, respectively.
We have the parallel component after addition be
Acos(a) + B
And the perpendicular component after addition be
Asin(a)
The magnitude of the resulting vector would be




As A and B are fixed, the equation above is maximum when cos(a) = 1, meaning a = 0 degree and vector A and B are in the same direction, and minimum with cos(a) = -1, meaning a = 180 degree and vector A and B are in opposite direction.
Answer:
1/2m or 0.5m
Explanation:
The formula to find the speed of a wave is given by:
V = frequency x wavelength
To find the wavelength, make the wavelength the subject of the formula
Therefore, wavelength = velocity ÷ frequency
Answer:
v_f = 10.85 m/s
Explanation:
We will apply the law of conservation of momentum here:

where,
m₁ = mass of roller skater = 47 kg
m₂ = mass of bag = 6 kg
v_1i = initial speed of roller skater = 12 m/s
v_2i = initial speed of the bag = 0 m/s
v_1f = final speed of the roller skater = ?
v_2f = final speed of the bag = ?
Both the bag and the skater will have same speed at the end because kater is carrying the bag:
v_1f = v_2f = v_f
Therefore, the equation will become:

<u>v_f = 10.85 m/s</u>