Answer:
(A) 3,449,600 N/m
(B) 62,720 poeple
Explanation:
extension of the sling shot (e) = 4 m
mass of projectile (m) = 440 g = 0.44 kg
speed of projectile (v) = 11.2 km/s = 11,200 m/s
average force a person can exert = 220 N
spring constant (k) = ?
(A) When all the elastic potential energy is converted to kinetic energy
rearranging the above equation
spring constant (K) = 
spring constant (K) = 
spring constant (K) = 
spring constant (K) = 3,449,600 N/m
(B) force required to stretch the slingshot (F) = ke = 3,449,600 x 4 = 13,798,400 N
number of people required = required force / average force per person = 13,798,400 / 220 =62,720 poeple
Answer:
option C
Explanation:
Let mass of the bullet be m and velocity be v
mass of gun be M and bullet be V
now,
using conservation of momentum for gun 1
(M+m) V' = 2 mv + 3 MV
V' = 0
3 M V = - 2 mv
momentum of gun 1 =- 2 mv---------(1)
now for gun 2
(M+m) V' = mv + MV
V' = 0
M V = - mv
momentum of gun 1 = -mv-----------(2)
dividing equation (1) by (2)
the correct answer is option C
Yes. On a circular path, the direction of motion is constantly changing. Change of direction is acceleration, even at constant speed.
Answer:
The difference between the cost of operating LED and incandescent bulb is $5.1
Explanation:
We are given the cost of electricity that is 12.75 cents per kWh. We want to find out the difference in the operating cost of an incandescent and LED bulb for a time period of 2,000 hours.
Since we are not given the rating of the incandescent bulb and LED bulb, we will assume their ratings.
For a light intensity of 250 Lumens;
The average rating of an LED bulb is approximately 5 Watts.
The average rating of an incandescent bulb is approximately 25 Watts.
Now lets find out the kWh of each bulb.
Energy = Power×Time
For LED bulb:
E = 5×2,000 = 10,000 Wh
Divide by 1000 to convert into kWh
E = 10,000/1000 = 10 kWh
Cost = 12.75×10 = 127.5 cents
Cost = $1.27
For Incandescent bulb:
E = 25×2,000 = 50,000 Wh
Divide by 1000 to convert into kWh
E = 50,000/1000 = 50 kWh
Cost = 12.75×50 = 637.5 cents
Cost = $6.37
Difference in Cost:
Difference = $6.37 - $1.27 = $5.1
Therefore, the difference between the cost of operating LED and incandescent bulb is $5.1.
Answer:
True
Explanation:
This Question is a little tricky, so I am unsure if this s the most logical answer.
If you'd look at a compass, 60 degrees south is moreover south then east, and the two imaginary lines are unlikely to intercept.
