Answer:
14.3kg
Explanation:
Given parameters:
Quantity of heat = 149000J
Change in temperature = 5.23°C
specific heat of the ice = 2000J/kg°C
Unknown:
Mass of the ice in the bag = ?
Solution:
The heat capacity of a substance is given as:
H = m c Ф
H is the heat capacity
m is the mass
c is the specific heat
Ф is the temperature change;
since m is the unknown, we make it the subject of the expression;
m = H/ mФ
m =
= 14.3kg
Answer:
24 Coulumbs
Explanation:
Given data
time= 1 minute= 6 seconds
P=2 W
R= 12 ohm
We know that
P= I^2R
P/R= I^2
2/12= I^2
I^2= 0.166
I= √0.166
I= 0.4 amps
We know also that
Q= It
substitute
Q= 0.4*60
Q= 24 Columbs
Hence the charge is 24 Coulumbs
Answer:
metals,nonmetals, and inert gases
Explanation:
We have the equation of motion
, where s is the displacement, a is the acceleration, u is the initial velocity and t is the time taken.
Here displacement = 135 m, Initial velocity = 0 m/s, acceleration = 9.81
Substituting

A box falls out of a stationary helicopter hovering 135 m above the ground will take 5.25 seconds to reach the ground.
Answer:
just before landing the ground
Explanation:
Let the velocity of projection is u and the angle of projection is 30°.
Let T is the time of flight and R is the horizontal distance traveled. As there is no force acting in horizontal direction, so the horizontal velocity remains constant. Let the particle hits the ground with velocity v.
initial horizontal component of velocity, ux = u Cos 30
initial vertical component of velocity, uy = u Sin 30
Time of flight is given by

Final horizontal component of velocity, vx = ux = u Cos 30
Let vy is teh final vertical component of velocity.
Use first equation of motion
vy = uy - gT


vy = - u Sin 30
The magnitude of final velocity is given by


v = u
Thus, the velocity is same as it just reaches the ground.