Answer:
T=26.03 N
Explanation:
Given that
Distance between poles = 12 m
Mass of block m= 4 kg
Sag distance = 5 m
Lets take tension in the clothesline is T.
The component of tension in vertical direction will be T cosθ.
By force balancing
2 T cosθ = 40
here
θ=39.80°
2 T cos39.8 = 40
T=26.03 N
Answer:
103.5 meters
Explanation:
Given that a stunt person has to jump from a bridge and land on a boat in the water 22.5 m below. The boat is cruising at a constant velocity of 48.3 m/s towards the bridge. The stunt person will jump up at 6.45 m/s as they leave the bridge.
The time the person will jump to a certain spot under the bridge can be calculated by using the formula below:
h = Ut + 1/2gt^2
since the person will fall under gravity, g = 9.8 m/s^2
Also, let assume that the person jump from rest, then, U = 0
Substitute h, U and g into the formula above
22.5 = 1/2 * 9.8 * t^2
22.5 = 4.9t^2
22.5 = 4.9t^2
t^2 = 22.5/4.9
t^2 = 4.59
t =
t = 2.143 seconds
From definition of speed,
speed = distance /time
Given that the boat is cruising at a constant velocity of 48.3 m/s towards the bridge, substitute the speed and the time to get the distance.
48.3 = distance / 2.143
distance = 48.3 * 2.143
distance = 103.5 m
Therefore, the boat should be 103.5m away from the bridge at the moment the stunt person jumps?
Answer:
ΔT = 302 °c
Explanation:
mass (m) = 4.6 g = 0.0046 kg
velocity (v) = 278 m/s
specific heat of lead (c) = 128 J/kg. °c
kinetic energy = 0.5 mx
kinetic energy = 0.5 x 0.0046 x
kinetic energy = 177.8 J
since all the kinetic energy is converted to thermal energy,
kinetic energy = thermal energy (E) = 177.8 J
thermal energy = m x c x ΔT
where ΔT is the temperature change
177.8 = 0.0046 x 128 x ΔT
ΔT = 177.8 / 0.59
ΔT = 302 °c