Answer:
time required after impact for a puck is 2.18 seconds
Explanation:
given data
mass = 30 g = 0.03 kg
diameter = 100 mm = 0.1 m
thick = 0.1 mm = 1 ×
m
dynamic viscosity = 1.75 ×
Ns/m²
air temperature = 15°C
to find out
time required after impact for a puck to lose 10%
solution
we know velocity varies here 0 to v
we consider here initial velocity = v
so final velocity = 0.9v
so change in velocity is du = v
and clearance dy = h
and shear stress acting on surface is here express as
= µ 
so
= µ
............1
put here value
= 1.75×
× 
= 0.175 v
and
area between air and puck is given by
Area =
area =
area = 7.85 ×
m²
so
force on puck is express as
Force = × area
force = 0.175 v × 7.85 × 
force = 1.374 ×
v
and now apply newton second law
force = mass × acceleration
- force = 
- 1.374 ×
v = 
t = 
time = 2.18
so time required after impact for a puck is 2.18 seconds
Answer:
What is u should know it bc u should answered it already
Explanation:
Solution:
Make an Observation - An indoor plant in a dark room withers faster than the same plant in a room with ample sunlight.
Ask a question- Why do certain indoor plants die faster based on where they are placed in the house?
State a hypothesis- Sunlight is probably essential for plants to grow and live.
Run an experiment- Get two potted plants. Cover one with black paper. Place both plants outside in sunlight. See what happens to each plant after one week.
Analyze the results-The plant in the pot with black paper withered. The other plant was healthy.
Communicate the results to others - Plants need sunlight to make food so they can live.
Ok so it would be late and the relative velocity would be 190 m/s because 200 m/s - 10 m/s is 190 m/s. Hope this helps.
Answer:5.17 m/s
Explanation:
Given
let u be the speed at cliff initial point
range over cliff is 1.45 m
and range of projectile is given by


u=3.77 m/s
Conserving Energy

Kinetic energy=Kinetic energy +Potential energy gained
Let v be the initial velocity




