A projectile is projected with an initial velocity of 40 m/s at a 45o angle to the horizontal. , calculate the total time travelled.

5.77 s

Explanation:

From the question,

The total time travelled by the projectile = Time of flight (T)

T = 2usinθ/g Equation 1

Where T = Time of Flight of the projectile, u = Initial velocity, θ = Angle of projection to the horizontal, g = acceleration due to gravity

Given: u = 40 m/s, θ = 45°

Constant: g = 9.8 m/s²

Substitute these values into equation 1

T = 2(40)sin(45°)/9.8

T = 80sin(45°)/9.8

T = 80×0.7071/9.8

T = 5.77 s

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

i do not get it   at all