Answer:
6.25 m/s
Explanation:
Given parameters
Initial mark = 65
Final mark = 15
time taken = 8s
Unknown:
Velocity of the runner = ?
Solution:
Velocity is the displacement divided by time;
Velocity =
Displacement = Initial mark - final mark = 65 - 15 = 50m
Now, insert the parameters and solve;
Velocity = = 6.25m/s
Answer:
0.71 kg
Explanation:
L = length of the steel wire = 3.0 m
d = diameter of steel wire = 0.32 mm = 0.32 x 10⁻³ m
Area of cross-section of the steel wire is given as
A = (0.25) πd²
A = (0.25) (3.14) (0.32 x 10⁻³)²
A = 8.04 x 10⁻⁸ m²
ΔL = change in length of the wire = 1.3 mm = 1.3 x 10⁻³ m
Y = Young's modulus of steel = 20 x 10¹⁰ Nm⁻²
m = mass hanging
F = weight of the mass hanging
Young's modulus of steel is given as
F = 6.968 N
Weight of the hanging mass is given as
F = mg
6.968 = m (9.8)
m = 0.71 kg
